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bme680_core.c
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linux-6.19.14/drivers/iio/chemical/bme680_core.c
1// SPDX-License-Identifier: GPL-2.0 2/* 3 * Bosch BME680 - Temperature, Pressure, Humidity & Gas Sensor 4 * 5 * Copyright (C) 2017 - 2018 Bosch Sensortec GmbH 6 * Copyright (C) 2018 Himanshu Jha <himanshujha199640@gmail.com> 7 * 8 * Datasheet: 9 * https://ae-bst.resource.bosch.com/media/_tech/media/datasheets/BST-BME680-DS001-00.pdf 10 */ 11#include <linux/bitfield.h> 12#include <linux/cleanup.h> 13#include <linux/delay.h> 14#include <linux/device.h> 15#include <linux/log2.h> 16#include <linux/module.h> 17#include <linux/pm.h> 18#include <linux/pm_runtime.h> 19#include <linux/regmap.h> 20#include <linux/regulator/consumer.h> 21 22#include <linux/iio/buffer.h> 23#include <linux/iio/iio.h> 24#include <linux/iio/sysfs.h> 25#include <linux/iio/trigger_consumer.h> 26#include <linux/iio/triggered_buffer.h> 27 28#include <linux/unaligned.h> 29 30#include "bme680.h" 31 32/* 1st set of calibration data */ 33enum { 34 /* Temperature calib indexes */ 35 T2_LSB = 0, 36 T3 = 2, 37 /* Pressure calib indexes */ 38 P1_LSB = 4, 39 P2_LSB = 6, 40 P3 = 8, 41 P4_LSB = 10, 42 P5_LSB = 12, 43 P7 = 14, 44 P6 = 15, 45 P8_LSB = 18, 46 P9_LSB = 20, 47 P10 = 22, 48}; 49 50/* 2nd set of calibration data */ 51enum { 52 /* Humidity calib indexes */ 53 H2_MSB = 0, 54 H1_LSB = 1, 55 H3 = 3, 56 H4 = 4, 57 H5 = 5, 58 H6 = 6, 59 H7 = 7, 60 /* Stray T1 calib index */ 61 T1_LSB = 8, 62 /* Gas heater calib indexes */ 63 GH2_LSB = 10, 64 GH1 = 12, 65 GH3 = 13, 66}; 67 68/* 3rd set of calibration data */ 69enum { 70 RES_HEAT_VAL = 0, 71 RES_HEAT_RANGE = 2, 72 RANGE_SW_ERR = 4, 73}; 74 75struct bme680_calib { 76 u16 par_t1; 77 s16 par_t2; 78 s8 par_t3; 79 u16 par_p1; 80 s16 par_p2; 81 s8 par_p3; 82 s16 par_p4; 83 s16 par_p5; 84 s8 par_p6; 85 s8 par_p7; 86 s16 par_p8; 87 s16 par_p9; 88 u8 par_p10; 89 u16 par_h1; 90 u16 par_h2; 91 s8 par_h3; 92 s8 par_h4; 93 s8 par_h5; 94 u8 par_h6; 95 s8 par_h7; 96 s8 par_gh1; 97 s16 par_gh2; 98 s8 par_gh3; 99 u8 res_heat_range; 100 s8 res_heat_val; 101 s8 range_sw_err; 102}; 103 104/* values of CTRL_MEAS register */ 105enum bme680_op_mode { 106 BME680_MODE_SLEEP = 0, 107 BME680_MODE_FORCED = 1, 108}; 109 110enum bme680_scan { 111 BME680_TEMP, 112 BME680_PRESS, 113 BME680_HUMID, 114 BME680_GAS, 115}; 116 117static const char *const bme680_supply_names[] = { "vdd", "vddio" }; 118 119struct bme680_data { 120 struct regmap *regmap; 121 struct bme680_calib bme680; 122 struct mutex lock; /* Protect multiple serial R/W ops to device. */ 123 u8 oversampling_temp; 124 u8 oversampling_press; 125 u8 oversampling_humid; 126 u8 preheat_curr_mA; 127 u16 heater_dur; 128 u16 heater_temp; 129 130 struct { 131 s32 chan[4]; 132 aligned_s64 ts; 133 } scan; 134 135 union { 136 u8 buf[BME680_NUM_BULK_READ_REGS]; 137 unsigned int check; 138 __be16 be16; 139 u8 bme680_cal_buf_1[BME680_CALIB_RANGE_1_LEN]; 140 u8 bme680_cal_buf_2[BME680_CALIB_RANGE_2_LEN]; 141 u8 bme680_cal_buf_3[BME680_CALIB_RANGE_3_LEN]; 142 }; 143}; 144 145static const struct regmap_range bme680_volatile_ranges[] = { 146 regmap_reg_range(BME680_REG_MEAS_STAT_0, BME680_REG_GAS_R_LSB), 147 regmap_reg_range(BME680_REG_STATUS, BME680_REG_STATUS), 148 regmap_reg_range(BME680_T2_LSB_REG, BME680_GH3_REG), 149}; 150 151static const struct regmap_access_table bme680_volatile_table = { 152 .yes_ranges = bme680_volatile_ranges, 153 .n_yes_ranges = ARRAY_SIZE(bme680_volatile_ranges), 154}; 155 156const struct regmap_config bme680_regmap_config = { 157 .reg_bits = 8, 158 .val_bits = 8, 159 .max_register = 0xef, 160 .volatile_table = &bme680_volatile_table, 161 .cache_type = REGCACHE_MAPLE, 162}; 163EXPORT_SYMBOL_NS(bme680_regmap_config, "IIO_BME680"); 164 165static const struct iio_chan_spec bme680_channels[] = { 166 { 167 .type = IIO_TEMP, 168 /* PROCESSED maintained for ABI backwards compatibility */ 169 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 170 BIT(IIO_CHAN_INFO_RAW) | 171 BIT(IIO_CHAN_INFO_SCALE) | 172 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 173 .scan_index = 0, 174 .scan_type = { 175 .sign = 's', 176 .realbits = 16, 177 .storagebits = 16, 178 .endianness = IIO_CPU, 179 }, 180 }, 181 { 182 .type = IIO_PRESSURE, 183 /* PROCESSED maintained for ABI backwards compatibility */ 184 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 185 BIT(IIO_CHAN_INFO_RAW) | 186 BIT(IIO_CHAN_INFO_SCALE) | 187 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 188 .scan_index = 1, 189 .scan_type = { 190 .sign = 'u', 191 .realbits = 32, 192 .storagebits = 32, 193 .endianness = IIO_CPU, 194 }, 195 }, 196 { 197 .type = IIO_HUMIDITYRELATIVE, 198 /* PROCESSED maintained for ABI backwards compatibility */ 199 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED) | 200 BIT(IIO_CHAN_INFO_RAW) | 201 BIT(IIO_CHAN_INFO_SCALE) | 202 BIT(IIO_CHAN_INFO_OVERSAMPLING_RATIO), 203 .scan_index = 2, 204 .scan_type = { 205 .sign = 'u', 206 .realbits = 32, 207 .storagebits = 32, 208 .endianness = IIO_CPU, 209 }, 210 }, 211 { 212 .type = IIO_RESISTANCE, 213 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 214 .scan_index = 3, 215 .scan_type = { 216 .sign = 'u', 217 .realbits = 32, 218 .storagebits = 32, 219 .endianness = IIO_CPU, 220 }, 221 }, 222 IIO_CHAN_SOFT_TIMESTAMP(4), 223 { 224 .type = IIO_CURRENT, 225 .info_mask_separate = BIT(IIO_CHAN_INFO_PROCESSED), 226 .output = 1, 227 .scan_index = -1, 228 }, 229}; 230 231static int bme680_read_calib(struct bme680_data *data, 232 struct bme680_calib *calib) 233{ 234 struct device *dev = regmap_get_device(data->regmap); 235 unsigned int tmp_msb, tmp_lsb; 236 int ret; 237 238 ret = regmap_bulk_read(data->regmap, BME680_T2_LSB_REG, 239 data->bme680_cal_buf_1, 240 sizeof(data->bme680_cal_buf_1)); 241 if (ret < 0) { 242 dev_err(dev, "failed to read 1st set of calib data;\n"); 243 return ret; 244 } 245 246 calib->par_t2 = get_unaligned_le16(&data->bme680_cal_buf_1[T2_LSB]); 247 calib->par_t3 = data->bme680_cal_buf_1[T3]; 248 calib->par_p1 = get_unaligned_le16(&data->bme680_cal_buf_1[P1_LSB]); 249 calib->par_p2 = get_unaligned_le16(&data->bme680_cal_buf_1[P2_LSB]); 250 calib->par_p3 = data->bme680_cal_buf_1[P3]; 251 calib->par_p4 = get_unaligned_le16(&data->bme680_cal_buf_1[P4_LSB]); 252 calib->par_p5 = get_unaligned_le16(&data->bme680_cal_buf_1[P5_LSB]); 253 calib->par_p7 = data->bme680_cal_buf_1[P7]; 254 calib->par_p6 = data->bme680_cal_buf_1[P6]; 255 calib->par_p8 = get_unaligned_le16(&data->bme680_cal_buf_1[P8_LSB]); 256 calib->par_p9 = get_unaligned_le16(&data->bme680_cal_buf_1[P9_LSB]); 257 calib->par_p10 = data->bme680_cal_buf_1[P10]; 258 259 ret = regmap_bulk_read(data->regmap, BME680_H2_MSB_REG, 260 data->bme680_cal_buf_2, 261 sizeof(data->bme680_cal_buf_2)); 262 if (ret < 0) { 263 dev_err(dev, "failed to read 2nd set of calib data;\n"); 264 return ret; 265 } 266 267 tmp_lsb = data->bme680_cal_buf_2[H1_LSB]; 268 tmp_msb = data->bme680_cal_buf_2[H1_LSB + 1]; 269 calib->par_h1 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 270 (tmp_lsb & BME680_BIT_H1_DATA_MASK); 271 272 tmp_msb = data->bme680_cal_buf_2[H2_MSB]; 273 tmp_lsb = data->bme680_cal_buf_2[H2_MSB + 1]; 274 calib->par_h2 = (tmp_msb << BME680_HUM_REG_SHIFT_VAL) | 275 (tmp_lsb >> BME680_HUM_REG_SHIFT_VAL); 276 277 calib->par_h3 = data->bme680_cal_buf_2[H3]; 278 calib->par_h4 = data->bme680_cal_buf_2[H4]; 279 calib->par_h5 = data->bme680_cal_buf_2[H5]; 280 calib->par_h6 = data->bme680_cal_buf_2[H6]; 281 calib->par_h7 = data->bme680_cal_buf_2[H7]; 282 calib->par_t1 = get_unaligned_le16(&data->bme680_cal_buf_2[T1_LSB]); 283 calib->par_gh2 = get_unaligned_le16(&data->bme680_cal_buf_2[GH2_LSB]); 284 calib->par_gh1 = data->bme680_cal_buf_2[GH1]; 285 calib->par_gh3 = data->bme680_cal_buf_2[GH3]; 286 287 ret = regmap_bulk_read(data->regmap, BME680_REG_RES_HEAT_VAL, 288 data->bme680_cal_buf_3, 289 sizeof(data->bme680_cal_buf_3)); 290 if (ret < 0) { 291 dev_err(dev, "failed to read 3rd set of calib data;\n"); 292 return ret; 293 } 294 295 calib->res_heat_val = data->bme680_cal_buf_3[RES_HEAT_VAL]; 296 297 calib->res_heat_range = FIELD_GET(BME680_RHRANGE_MASK, 298 data->bme680_cal_buf_3[RES_HEAT_RANGE]); 299 300 calib->range_sw_err = FIELD_GET(BME680_RSERROR_MASK, 301 data->bme680_cal_buf_3[RANGE_SW_ERR]); 302 303 return 0; 304} 305 306static int bme680_read_temp_adc(struct bme680_data *data, u32 *adc_temp) 307{ 308 struct device *dev = regmap_get_device(data->regmap); 309 u32 value_temp; 310 int ret; 311 312 ret = regmap_bulk_read(data->regmap, BME680_REG_TEMP_MSB, 313 data->buf, BME680_TEMP_NUM_BYTES); 314 if (ret < 0) { 315 dev_err(dev, "failed to read temperature\n"); 316 return ret; 317 } 318 319 value_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, 320 get_unaligned_be24(data->buf)); 321 if (value_temp == BME680_MEAS_SKIPPED) { 322 /* reading was skipped */ 323 dev_err(dev, "reading temperature skipped\n"); 324 return -EINVAL; 325 } 326 *adc_temp = value_temp; 327 328 return 0; 329} 330 331/* 332 * Taken from Bosch BME680 API: 333 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L876 334 * 335 * Returns temperature measurement in DegC, resolutions is 0.01 DegC. Therefore, 336 * output value of "3233" represents 32.33 DegC. 337 */ 338static s32 bme680_calc_t_fine(struct bme680_data *data, u32 adc_temp) 339{ 340 struct bme680_calib *calib = &data->bme680; 341 s64 var1, var2, var3; 342 343 /* If the calibration is invalid, attempt to reload it */ 344 if (!calib->par_t2) 345 bme680_read_calib(data, calib); 346 347 var1 = ((s32)adc_temp >> 3) - ((s32)calib->par_t1 << 1); 348 var2 = (var1 * calib->par_t2) >> 11; 349 var3 = ((var1 >> 1) * (var1 >> 1)) >> 12; 350 var3 = (var3 * ((s32)calib->par_t3 << 4)) >> 14; 351 return var2 + var3; /* t_fine = var2 + var3 */ 352} 353 354static int bme680_get_t_fine(struct bme680_data *data, s32 *t_fine) 355{ 356 u32 adc_temp; 357 int ret; 358 359 ret = bme680_read_temp_adc(data, &adc_temp); 360 if (ret) 361 return ret; 362 363 *t_fine = bme680_calc_t_fine(data, adc_temp); 364 365 return 0; 366} 367 368static s16 bme680_compensate_temp(struct bme680_data *data, 369 u32 adc_temp) 370{ 371 return (bme680_calc_t_fine(data, adc_temp) * 5 + 128) / 256; 372} 373 374static int bme680_read_press_adc(struct bme680_data *data, u32 *adc_press) 375{ 376 struct device *dev = regmap_get_device(data->regmap); 377 u32 value_press; 378 int ret; 379 380 ret = regmap_bulk_read(data->regmap, BME680_REG_PRESS_MSB, 381 data->buf, BME680_PRESS_NUM_BYTES); 382 if (ret < 0) { 383 dev_err(dev, "failed to read pressure\n"); 384 return ret; 385 } 386 387 value_press = FIELD_GET(BME680_MEAS_TRIM_MASK, 388 get_unaligned_be24(data->buf)); 389 if (value_press == BME680_MEAS_SKIPPED) { 390 /* reading was skipped */ 391 dev_err(dev, "reading pressure skipped\n"); 392 return -EINVAL; 393 } 394 *adc_press = value_press; 395 396 return 0; 397} 398 399/* 400 * Taken from Bosch BME680 API: 401 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L896 402 * 403 * Returns pressure measurement in Pa. Output value of "97356" represents 404 * 97356 Pa = 973.56 hPa. 405 */ 406static u32 bme680_compensate_press(struct bme680_data *data, 407 u32 adc_press, s32 t_fine) 408{ 409 struct bme680_calib *calib = &data->bme680; 410 s32 var1, var2, var3, press_comp; 411 412 var1 = (t_fine >> 1) - 64000; 413 var2 = ((((var1 >> 2) * (var1 >> 2)) >> 11) * calib->par_p6) >> 2; 414 var2 = var2 + (var1 * calib->par_p5 << 1); 415 var2 = (var2 >> 2) + ((s32)calib->par_p4 << 16); 416 var1 = (((((var1 >> 2) * (var1 >> 2)) >> 13) * 417 ((s32)calib->par_p3 << 5)) >> 3) + 418 ((calib->par_p2 * var1) >> 1); 419 var1 = var1 >> 18; 420 var1 = ((32768 + var1) * calib->par_p1) >> 15; 421 press_comp = 1048576 - adc_press; 422 press_comp = ((press_comp - (var2 >> 12)) * 3125); 423 424 if (press_comp >= BME680_MAX_OVERFLOW_VAL) 425 press_comp = ((press_comp / (u32)var1) << 1); 426 else 427 press_comp = ((press_comp << 1) / (u32)var1); 428 429 var1 = (calib->par_p9 * (((press_comp >> 3) * 430 (press_comp >> 3)) >> 13)) >> 12; 431 var2 = ((press_comp >> 2) * calib->par_p8) >> 13; 432 var3 = ((press_comp >> 8) * (press_comp >> 8) * 433 (press_comp >> 8) * calib->par_p10) >> 17; 434 435 press_comp += (var1 + var2 + var3 + ((s32)calib->par_p7 << 7)) >> 4; 436 437 return press_comp; 438} 439 440static int bme680_read_humid_adc(struct bme680_data *data, u32 *adc_humidity) 441{ 442 struct device *dev = regmap_get_device(data->regmap); 443 u32 value_humidity; 444 int ret; 445 446 ret = regmap_bulk_read(data->regmap, BME680_REG_HUMIDITY_MSB, 447 &data->be16, BME680_HUMID_NUM_BYTES); 448 if (ret < 0) { 449 dev_err(dev, "failed to read humidity\n"); 450 return ret; 451 } 452 453 value_humidity = be16_to_cpu(data->be16); 454 if (value_humidity == BME680_MEAS_SKIPPED) { 455 /* reading was skipped */ 456 dev_err(dev, "reading humidity skipped\n"); 457 return -EINVAL; 458 } 459 *adc_humidity = value_humidity; 460 461 return 0; 462} 463 464/* 465 * Taken from Bosch BME680 API: 466 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L937 467 * 468 * Returns humidity measurement in percent, resolution is 0.001 percent. Output 469 * value of "43215" represents 43.215 %rH. 470 */ 471static u32 bme680_compensate_humid(struct bme680_data *data, 472 u16 adc_humid, s32 t_fine) 473{ 474 struct bme680_calib *calib = &data->bme680; 475 s32 var1, var2, var3, var4, var5, var6, temp_scaled, calc_hum; 476 477 temp_scaled = (t_fine * 5 + 128) >> 8; 478 var1 = (adc_humid - (((s32)calib->par_h1 * 16))) - 479 (((temp_scaled * calib->par_h3) / 100) >> 1); 480 var2 = (calib->par_h2 * 481 (((temp_scaled * calib->par_h4) / 100) + 482 (((temp_scaled * ((temp_scaled * calib->par_h5) / 100)) 483 >> 6) / 100) + (1 << 14))) >> 10; 484 var3 = var1 * var2; 485 var4 = (s32)calib->par_h6 << 7; 486 var4 = (var4 + ((temp_scaled * calib->par_h7) / 100)) >> 4; 487 var5 = ((var3 >> 14) * (var3 >> 14)) >> 10; 488 var6 = (var4 * var5) >> 1; 489 calc_hum = (((var3 + var6) >> 10) * 1000) >> 12; 490 491 calc_hum = clamp(calc_hum, 0, 100000); /* clamp between 0-100 %rH */ 492 493 return calc_hum; 494} 495 496/* 497 * Taken from Bosch BME680 API: 498 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L973 499 * 500 * Returns gas measurement in Ohm. Output value of "82986" represent 82986 ohms. 501 */ 502static u32 bme680_compensate_gas(struct bme680_data *data, u16 gas_res_adc, 503 u8 gas_range) 504{ 505 struct bme680_calib *calib = &data->bme680; 506 s64 var1; 507 u64 var2; 508 s64 var3; 509 u32 calc_gas_res; 510 511 /* Look up table for the possible gas range values */ 512 static const u32 lookup_table[16] = { 513 2147483647u, 2147483647u, 2147483647u, 2147483647u, 514 2147483647u, 2126008810u, 2147483647u, 2130303777u, 515 2147483647u, 2147483647u, 2143188679u, 2136746228u, 516 2147483647u, 2126008810u, 2147483647u, 2147483647u 517 }; 518 519 var1 = ((1340LL + (5 * calib->range_sw_err)) * 520 (lookup_table[gas_range])) >> 16; 521 var2 = ((gas_res_adc << 15) - 16777216) + var1; 522 var3 = ((125000 << (15 - gas_range)) * var1) >> 9; 523 var3 += (var2 >> 1); 524 calc_gas_res = div64_s64(var3, (s64)var2); 525 526 return calc_gas_res; 527} 528 529/* 530 * Taken from Bosch BME680 API: 531 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1002 532 */ 533static u8 bme680_calc_heater_res(struct bme680_data *data, u16 temp) 534{ 535 struct bme680_calib *calib = &data->bme680; 536 s32 var1, var2, var3, var4, var5, heatr_res_x100; 537 u8 heatr_res; 538 539 if (temp > 400) /* Cap temperature */ 540 temp = 400; 541 542 var1 = (((s32)BME680_AMB_TEMP * calib->par_gh3) / 1000) * 256; 543 var2 = (calib->par_gh1 + 784) * (((((calib->par_gh2 + 154009) * 544 temp * 5) / 100) 545 + 3276800) / 10); 546 var3 = var1 + (var2 / 2); 547 var4 = (var3 / (calib->res_heat_range + 4)); 548 var5 = 131 * calib->res_heat_val + 65536; 549 heatr_res_x100 = ((var4 / var5) - 250) * 34; 550 heatr_res = DIV_ROUND_CLOSEST(heatr_res_x100, 100); 551 552 return heatr_res; 553} 554 555/* 556 * Taken from Bosch BME680 API: 557 * https://github.com/BoschSensortec/BME680_driver/blob/63bb5336/bme680.c#L1188 558 */ 559static u8 bme680_calc_heater_dur(u16 dur) 560{ 561 u8 durval, factor = 0; 562 563 if (dur >= 0xfc0) { 564 durval = 0xff; /* Max duration */ 565 } else { 566 while (dur > 0x3F) { 567 dur = dur / 4; 568 factor += 1; 569 } 570 durval = dur + (factor * 64); 571 } 572 573 return durval; 574} 575 576/* Taken from datasheet, section 5.3.3 */ 577static u8 bme680_calc_heater_preheat_current(u8 curr) 578{ 579 return 8 * curr - 1; 580} 581 582static int bme680_set_mode(struct bme680_data *data, enum bme680_op_mode mode) 583{ 584 struct device *dev = regmap_get_device(data->regmap); 585 int ret; 586 587 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 588 BME680_MODE_MASK, mode); 589 if (ret < 0) { 590 dev_err(dev, "failed to set ctrl_meas register\n"); 591 return ret; 592 } 593 594 return ret; 595} 596 597static u8 bme680_oversampling_to_reg(u8 val) 598{ 599 return ilog2(val) + 1; 600} 601 602/* 603 * Taken from Bosch BME680 API: 604 * https://github.com/boschsensortec/BME68x_SensorAPI/blob/v4.4.8/bme68x.c#L490 605 */ 606static int bme680_wait_for_eoc(struct bme680_data *data) 607{ 608 struct device *dev = regmap_get_device(data->regmap); 609 int ret; 610 /* 611 * (Sum of oversampling ratios * time per oversampling) + 612 * TPH measurement + gas measurement + wait transition from forced mode 613 * + heater duration 614 */ 615 int wait_eoc_us = ((data->oversampling_temp + data->oversampling_press + 616 data->oversampling_humid) * 1963) + (477 * 4) + 617 (477 * 5) + 1000 + (data->heater_dur * 1000); 618 619 fsleep(wait_eoc_us); 620 621 ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); 622 if (ret) { 623 dev_err(dev, "failed to read measurement status register.\n"); 624 return ret; 625 } 626 if (data->check & BME680_MEAS_BIT) { 627 dev_err(dev, "Device measurement cycle incomplete.\n"); 628 return -EBUSY; 629 } 630 if (!(data->check & BME680_NEW_DATA_BIT)) { 631 dev_err(dev, "No new data available from the device.\n"); 632 return -ENODATA; 633 } 634 635 return 0; 636} 637 638static int bme680_chip_config(struct bme680_data *data) 639{ 640 struct device *dev = regmap_get_device(data->regmap); 641 int ret; 642 u8 osrs; 643 644 osrs = FIELD_PREP(BME680_OSRS_HUMIDITY_MASK, 645 bme680_oversampling_to_reg(data->oversampling_humid)); 646 /* 647 * Highly recommended to set oversampling of humidity before 648 * temperature/pressure oversampling. 649 */ 650 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_HUMIDITY, 651 BME680_OSRS_HUMIDITY_MASK, osrs); 652 if (ret < 0) { 653 dev_err(dev, "failed to write ctrl_hum register\n"); 654 return ret; 655 } 656 657 /* IIR filter settings */ 658 ret = regmap_update_bits(data->regmap, BME680_REG_CONFIG, 659 BME680_FILTER_MASK, BME680_FILTER_COEFF_VAL); 660 if (ret < 0) { 661 dev_err(dev, "failed to write config register\n"); 662 return ret; 663 } 664 665 osrs = FIELD_PREP(BME680_OSRS_TEMP_MASK, 666 bme680_oversampling_to_reg(data->oversampling_temp)) | 667 FIELD_PREP(BME680_OSRS_PRESS_MASK, 668 bme680_oversampling_to_reg(data->oversampling_press)); 669 ret = regmap_write_bits(data->regmap, BME680_REG_CTRL_MEAS, 670 BME680_OSRS_TEMP_MASK | BME680_OSRS_PRESS_MASK, 671 osrs); 672 if (ret < 0) { 673 dev_err(dev, "failed to write ctrl_meas register\n"); 674 return ret; 675 } 676 677 return 0; 678} 679 680static int bme680_preheat_curr_config(struct bme680_data *data, u8 val) 681{ 682 struct device *dev = regmap_get_device(data->regmap); 683 u8 heatr_curr; 684 int ret; 685 686 heatr_curr = bme680_calc_heater_preheat_current(val); 687 ret = regmap_write(data->regmap, BME680_REG_IDAC_HEAT_0, heatr_curr); 688 if (ret < 0) 689 dev_err(dev, "failed to write idac_heat_0 register\n"); 690 691 return ret; 692} 693 694static int bme680_gas_config(struct bme680_data *data) 695{ 696 struct device *dev = regmap_get_device(data->regmap); 697 int ret; 698 u8 heatr_res, heatr_dur; 699 700 ret = bme680_set_mode(data, BME680_MODE_SLEEP); 701 if (ret < 0) 702 return ret; 703 704 heatr_res = bme680_calc_heater_res(data, data->heater_temp); 705 706 /* set target heater temperature */ 707 ret = regmap_write(data->regmap, BME680_REG_RES_HEAT_0, heatr_res); 708 if (ret < 0) { 709 dev_err(dev, "failed to write res_heat_0 register\n"); 710 return ret; 711 } 712 713 heatr_dur = bme680_calc_heater_dur(data->heater_dur); 714 715 /* set target heating duration */ 716 ret = regmap_write(data->regmap, BME680_REG_GAS_WAIT_0, heatr_dur); 717 if (ret < 0) { 718 dev_err(dev, "failed to write gas_wait_0 register\n"); 719 return ret; 720 } 721 722 ret = bme680_preheat_curr_config(data, data->preheat_curr_mA); 723 if (ret) 724 return ret; 725 726 /* Enable the gas sensor and select heater profile set-point 0 */ 727 ret = regmap_update_bits(data->regmap, BME680_REG_CTRL_GAS_1, 728 BME680_RUN_GAS_MASK | BME680_NB_CONV_MASK, 729 FIELD_PREP(BME680_RUN_GAS_MASK, 1) | 730 FIELD_PREP(BME680_NB_CONV_MASK, 0)); 731 if (ret < 0) 732 dev_err(dev, "failed to write ctrl_gas_1 register\n"); 733 734 return ret; 735} 736 737static int bme680_read_temp(struct bme680_data *data, s16 *comp_temp) 738{ 739 int ret; 740 u32 adc_temp; 741 742 ret = bme680_read_temp_adc(data, &adc_temp); 743 if (ret) 744 return ret; 745 746 *comp_temp = bme680_compensate_temp(data, adc_temp); 747 return 0; 748} 749 750static int bme680_read_press(struct bme680_data *data, u32 *comp_press) 751{ 752 int ret; 753 u32 adc_press; 754 s32 t_fine; 755 756 ret = bme680_get_t_fine(data, &t_fine); 757 if (ret) 758 return ret; 759 760 ret = bme680_read_press_adc(data, &adc_press); 761 if (ret) 762 return ret; 763 764 *comp_press = bme680_compensate_press(data, adc_press, t_fine); 765 return 0; 766} 767 768static int bme680_read_humid(struct bme680_data *data, u32 *comp_humidity) 769{ 770 int ret; 771 u32 adc_humidity; 772 s32 t_fine; 773 774 ret = bme680_get_t_fine(data, &t_fine); 775 if (ret) 776 return ret; 777 778 ret = bme680_read_humid_adc(data, &adc_humidity); 779 if (ret) 780 return ret; 781 782 *comp_humidity = bme680_compensate_humid(data, adc_humidity, t_fine); 783 return 0; 784} 785 786static int bme680_read_gas(struct bme680_data *data, int *comp_gas_res) 787{ 788 struct device *dev = regmap_get_device(data->regmap); 789 int ret; 790 u16 adc_gas_res, gas_regs_val; 791 u8 gas_range; 792 793 ret = regmap_read(data->regmap, BME680_REG_MEAS_STAT_0, &data->check); 794 if (data->check & BME680_GAS_MEAS_BIT) { 795 dev_err(dev, "gas measurement incomplete\n"); 796 return -EBUSY; 797 } 798 799 ret = regmap_bulk_read(data->regmap, BME680_REG_GAS_MSB, 800 &data->be16, BME680_GAS_NUM_BYTES); 801 if (ret < 0) { 802 dev_err(dev, "failed to read gas resistance\n"); 803 return ret; 804 } 805 806 gas_regs_val = be16_to_cpu(data->be16); 807 adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val); 808 809 /* 810 * occurs if either the gas heating duration was insuffient 811 * to reach the target heater temperature or the target 812 * heater temperature was too high for the heater sink to 813 * reach. 814 */ 815 if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) { 816 dev_err(dev, "heater failed to reach the target temperature\n"); 817 return -EINVAL; 818 } 819 820 gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val); 821 *comp_gas_res = bme680_compensate_gas(data, adc_gas_res, gas_range); 822 return 0; 823} 824 825static int __bme680_read_raw(struct iio_dev *indio_dev, 826 struct iio_chan_spec const *chan, 827 int *val, int *val2, long mask) 828{ 829 struct bme680_data *data = iio_priv(indio_dev); 830 int chan_val, ret; 831 s16 temp_chan_val; 832 833 guard(mutex)(&data->lock); 834 835 ret = bme680_set_mode(data, BME680_MODE_FORCED); 836 if (ret < 0) 837 return ret; 838 839 ret = bme680_wait_for_eoc(data); 840 if (ret) 841 return ret; 842 843 switch (mask) { 844 case IIO_CHAN_INFO_PROCESSED: 845 switch (chan->type) { 846 case IIO_TEMP: 847 ret = bme680_read_temp(data, &temp_chan_val); 848 if (ret) 849 return ret; 850 851 *val = temp_chan_val * 10; 852 return IIO_VAL_INT; 853 case IIO_PRESSURE: 854 ret = bme680_read_press(data, &chan_val); 855 if (ret) 856 return ret; 857 858 *val = chan_val; 859 *val2 = 1000; 860 return IIO_VAL_FRACTIONAL; 861 case IIO_HUMIDITYRELATIVE: 862 ret = bme680_read_humid(data, &chan_val); 863 if (ret) 864 return ret; 865 866 *val = chan_val; 867 *val2 = 1000; 868 return IIO_VAL_FRACTIONAL; 869 case IIO_RESISTANCE: 870 ret = bme680_read_gas(data, &chan_val); 871 if (ret) 872 return ret; 873 874 *val = chan_val; 875 return IIO_VAL_INT; 876 default: 877 return -EINVAL; 878 } 879 case IIO_CHAN_INFO_RAW: 880 switch (chan->type) { 881 case IIO_TEMP: 882 ret = bme680_read_temp(data, &temp_chan_val); 883 if (ret) 884 return ret; 885 886 *val = temp_chan_val; 887 return IIO_VAL_INT; 888 case IIO_PRESSURE: 889 ret = bme680_read_press(data, &chan_val); 890 if (ret) 891 return ret; 892 893 *val = chan_val; 894 return IIO_VAL_INT; 895 case IIO_HUMIDITYRELATIVE: 896 ret = bme680_read_humid(data, &chan_val); 897 if (ret) 898 return ret; 899 900 *val = chan_val; 901 return IIO_VAL_INT; 902 default: 903 return -EINVAL; 904 } 905 case IIO_CHAN_INFO_SCALE: 906 switch (chan->type) { 907 case IIO_TEMP: 908 *val = 10; 909 return IIO_VAL_INT; 910 case IIO_PRESSURE: 911 *val = 1; 912 *val2 = 1000; 913 return IIO_VAL_FRACTIONAL; 914 case IIO_HUMIDITYRELATIVE: 915 *val = 1; 916 *val2 = 1000; 917 return IIO_VAL_FRACTIONAL; 918 default: 919 return -EINVAL; 920 } 921 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 922 switch (chan->type) { 923 case IIO_TEMP: 924 *val = data->oversampling_temp; 925 return IIO_VAL_INT; 926 case IIO_PRESSURE: 927 *val = data->oversampling_press; 928 return IIO_VAL_INT; 929 case IIO_HUMIDITYRELATIVE: 930 *val = data->oversampling_humid; 931 return IIO_VAL_INT; 932 default: 933 return -EINVAL; 934 } 935 default: 936 return -EINVAL; 937 } 938} 939 940static int bme680_read_raw(struct iio_dev *indio_dev, 941 struct iio_chan_spec const *chan, 942 int *val, int *val2, long mask) 943{ 944 struct bme680_data *data = iio_priv(indio_dev); 945 struct device *dev = regmap_get_device(data->regmap); 946 int ret; 947 948 ret = pm_runtime_resume_and_get(dev); 949 if (ret) 950 return ret; 951 952 ret = __bme680_read_raw(indio_dev, chan, val, val2, mask); 953 pm_runtime_put_autosuspend(dev); 954 955 return ret; 956} 957 958static bool bme680_is_valid_oversampling(int rate) 959{ 960 return (rate > 0 && rate <= 16 && is_power_of_2(rate)); 961} 962 963static int __bme680_write_raw(struct iio_dev *indio_dev, 964 struct iio_chan_spec const *chan, 965 int val, int val2, long mask) 966{ 967 struct bme680_data *data = iio_priv(indio_dev); 968 969 guard(mutex)(&data->lock); 970 971 if (val2 != 0) 972 return -EINVAL; 973 974 switch (mask) { 975 case IIO_CHAN_INFO_OVERSAMPLING_RATIO: 976 { 977 if (!bme680_is_valid_oversampling(val)) 978 return -EINVAL; 979 980 switch (chan->type) { 981 case IIO_TEMP: 982 data->oversampling_temp = val; 983 break; 984 case IIO_PRESSURE: 985 data->oversampling_press = val; 986 break; 987 case IIO_HUMIDITYRELATIVE: 988 data->oversampling_humid = val; 989 break; 990 default: 991 return -EINVAL; 992 } 993 994 return bme680_chip_config(data); 995 } 996 case IIO_CHAN_INFO_PROCESSED: 997 { 998 switch (chan->type) { 999 case IIO_CURRENT: 1000 return bme680_preheat_curr_config(data, (u8)val); 1001 default: 1002 return -EINVAL; 1003 } 1004 } 1005 default: 1006 return -EINVAL; 1007 } 1008} 1009 1010static int bme680_write_raw(struct iio_dev *indio_dev, 1011 struct iio_chan_spec const *chan, 1012 int val, int val2, long mask) 1013{ 1014 struct bme680_data *data = iio_priv(indio_dev); 1015 struct device *dev = regmap_get_device(data->regmap); 1016 int ret; 1017 1018 ret = pm_runtime_resume_and_get(dev); 1019 if (ret) 1020 return ret; 1021 1022 ret = __bme680_write_raw(indio_dev, chan, val, val2, mask); 1023 pm_runtime_put_autosuspend(dev); 1024 1025 return ret; 1026} 1027 1028static const char bme680_oversampling_ratio_show[] = "1 2 4 8 16"; 1029 1030static IIO_CONST_ATTR(oversampling_ratio_available, 1031 bme680_oversampling_ratio_show); 1032 1033static struct attribute *bme680_attributes[] = { 1034 &iio_const_attr_oversampling_ratio_available.dev_attr.attr, 1035 NULL, 1036}; 1037 1038static const struct attribute_group bme680_attribute_group = { 1039 .attrs = bme680_attributes, 1040}; 1041 1042static const struct iio_info bme680_info = { 1043 .read_raw = &bme680_read_raw, 1044 .write_raw = &bme680_write_raw, 1045 .attrs = &bme680_attribute_group, 1046}; 1047 1048static const unsigned long bme680_avail_scan_masks[] = { 1049 BIT(BME680_GAS) | BIT(BME680_HUMID) | BIT(BME680_PRESS) | BIT(BME680_TEMP), 1050 0 1051}; 1052 1053static irqreturn_t bme680_trigger_handler(int irq, void *p) 1054{ 1055 struct iio_poll_func *pf = p; 1056 struct iio_dev *indio_dev = pf->indio_dev; 1057 struct bme680_data *data = iio_priv(indio_dev); 1058 struct device *dev = regmap_get_device(data->regmap); 1059 u32 adc_temp, adc_press, adc_humid; 1060 u16 adc_gas_res, gas_regs_val; 1061 u8 gas_range; 1062 s32 t_fine; 1063 int ret; 1064 1065 guard(mutex)(&data->lock); 1066 1067 ret = bme680_set_mode(data, BME680_MODE_FORCED); 1068 if (ret < 0) 1069 goto out; 1070 1071 ret = bme680_wait_for_eoc(data); 1072 if (ret) 1073 goto out; 1074 1075 ret = regmap_bulk_read(data->regmap, BME680_REG_MEAS_STAT_0, 1076 data->buf, sizeof(data->buf)); 1077 if (ret) { 1078 dev_err(dev, "failed to burst read sensor data\n"); 1079 goto out; 1080 } 1081 if (data->buf[0] & BME680_GAS_MEAS_BIT) { 1082 dev_err(dev, "gas measurement incomplete\n"); 1083 goto out; 1084 } 1085 1086 /* Temperature calculations */ 1087 adc_temp = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[5])); 1088 if (adc_temp == BME680_MEAS_SKIPPED) { 1089 dev_err(dev, "reading temperature skipped\n"); 1090 goto out; 1091 } 1092 data->scan.chan[0] = bme680_compensate_temp(data, adc_temp); 1093 t_fine = bme680_calc_t_fine(data, adc_temp); 1094 1095 /* Pressure calculations */ 1096 adc_press = FIELD_GET(BME680_MEAS_TRIM_MASK, get_unaligned_be24(&data->buf[2])); 1097 if (adc_press == BME680_MEAS_SKIPPED) { 1098 dev_err(dev, "reading pressure skipped\n"); 1099 goto out; 1100 } 1101 data->scan.chan[1] = bme680_compensate_press(data, adc_press, t_fine); 1102 1103 /* Humidity calculations */ 1104 adc_humid = get_unaligned_be16(&data->buf[8]); 1105 if (adc_humid == BME680_MEAS_SKIPPED) { 1106 dev_err(dev, "reading humidity skipped\n"); 1107 goto out; 1108 } 1109 data->scan.chan[2] = bme680_compensate_humid(data, adc_humid, t_fine); 1110 1111 /* Gas calculations */ 1112 gas_regs_val = get_unaligned_be16(&data->buf[13]); 1113 adc_gas_res = FIELD_GET(BME680_ADC_GAS_RES, gas_regs_val); 1114 if ((gas_regs_val & BME680_GAS_STAB_BIT) == 0) { 1115 dev_err(dev, "heater failed to reach the target temperature\n"); 1116 goto out; 1117 } 1118 gas_range = FIELD_GET(BME680_GAS_RANGE_MASK, gas_regs_val); 1119 data->scan.chan[3] = bme680_compensate_gas(data, adc_gas_res, gas_range); 1120 1121 iio_push_to_buffers_with_ts(indio_dev, &data->scan, sizeof(data->scan), 1122 iio_get_time_ns(indio_dev)); 1123out: 1124 iio_trigger_notify_done(indio_dev->trig); 1125 return IRQ_HANDLED; 1126} 1127 1128static int bme680_buffer_preenable(struct iio_dev *indio_dev) 1129{ 1130 struct bme680_data *data = iio_priv(indio_dev); 1131 struct device *dev = regmap_get_device(data->regmap); 1132 1133 return pm_runtime_resume_and_get(dev); 1134} 1135 1136static int bme680_buffer_postdisable(struct iio_dev *indio_dev) 1137{ 1138 struct bme680_data *data = iio_priv(indio_dev); 1139 struct device *dev = regmap_get_device(data->regmap); 1140 1141 pm_runtime_put_autosuspend(dev); 1142 return 0; 1143} 1144 1145static const struct iio_buffer_setup_ops bme680_buffer_setup_ops = { 1146 .preenable = bme680_buffer_preenable, 1147 .postdisable = bme680_buffer_postdisable, 1148}; 1149 1150int bme680_core_probe(struct device *dev, struct regmap *regmap, 1151 const char *name) 1152{ 1153 struct iio_dev *indio_dev; 1154 struct bme680_data *data; 1155 int ret; 1156 1157 indio_dev = devm_iio_device_alloc(dev, sizeof(*data)); 1158 if (!indio_dev) 1159 return -ENOMEM; 1160 1161 data = iio_priv(indio_dev); 1162 mutex_init(&data->lock); 1163 dev_set_drvdata(dev, indio_dev); 1164 data->regmap = regmap; 1165 indio_dev->name = name; 1166 indio_dev->channels = bme680_channels; 1167 indio_dev->num_channels = ARRAY_SIZE(bme680_channels); 1168 indio_dev->available_scan_masks = bme680_avail_scan_masks; 1169 indio_dev->info = &bme680_info; 1170 indio_dev->modes = INDIO_DIRECT_MODE; 1171 1172 /* default values for the sensor */ 1173 data->oversampling_humid = 2; /* 2X oversampling rate */ 1174 data->oversampling_press = 4; /* 4X oversampling rate */ 1175 data->oversampling_temp = 8; /* 8X oversampling rate */ 1176 data->heater_temp = 320; /* degree Celsius */ 1177 data->heater_dur = 150; /* milliseconds */ 1178 data->preheat_curr_mA = 0; 1179 1180 ret = devm_regulator_bulk_get_enable(dev, ARRAY_SIZE(bme680_supply_names), 1181 bme680_supply_names); 1182 if (ret) 1183 return dev_err_probe(dev, ret, 1184 "failed to get and enable supplies.\n"); 1185 1186 fsleep(BME680_STARTUP_TIME_US); 1187 1188 ret = regmap_write(regmap, BME680_REG_SOFT_RESET, BME680_CMD_SOFTRESET); 1189 if (ret < 0) 1190 return dev_err_probe(dev, ret, "Failed to reset chip\n"); 1191 1192 fsleep(BME680_STARTUP_TIME_US); 1193 1194 ret = regmap_read(regmap, BME680_REG_CHIP_ID, &data->check); 1195 if (ret < 0) 1196 return dev_err_probe(dev, ret, "Error reading chip ID\n"); 1197 1198 if (data->check != BME680_CHIP_ID_VAL) { 1199 dev_err(dev, "Wrong chip ID, got %x expected %x\n", 1200 data->check, BME680_CHIP_ID_VAL); 1201 return -ENODEV; 1202 } 1203 1204 ret = bme680_read_calib(data, &data->bme680); 1205 if (ret < 0) { 1206 return dev_err_probe(dev, ret, 1207 "failed to read calibration coefficients at probe\n"); 1208 } 1209 1210 ret = bme680_chip_config(data); 1211 if (ret < 0) 1212 return dev_err_probe(dev, ret, 1213 "failed to set chip_config data\n"); 1214 1215 ret = bme680_gas_config(data); 1216 if (ret < 0) 1217 return dev_err_probe(dev, ret, 1218 "failed to set gas config data\n"); 1219 1220 ret = devm_iio_triggered_buffer_setup(dev, indio_dev, 1221 iio_pollfunc_store_time, 1222 bme680_trigger_handler, 1223 &bme680_buffer_setup_ops); 1224 if (ret) 1225 return dev_err_probe(dev, ret, 1226 "iio triggered buffer setup failed\n"); 1227 1228 /* Enable runtime PM */ 1229 pm_runtime_set_autosuspend_delay(dev, BME680_STARTUP_TIME_US); 1230 pm_runtime_use_autosuspend(dev); 1231 pm_runtime_set_active(dev); 1232 ret = devm_pm_runtime_enable(dev); 1233 if (ret) 1234 return ret; 1235 1236 return devm_iio_device_register(dev, indio_dev); 1237} 1238EXPORT_SYMBOL_NS_GPL(bme680_core_probe, "IIO_BME680"); 1239 1240static int bme680_runtime_suspend(struct device *dev) 1241{ 1242 struct iio_dev *indio_dev = dev_get_drvdata(dev); 1243 struct bme680_data *data = iio_priv(indio_dev); 1244 1245 return bme680_set_mode(data, BME680_MODE_SLEEP); 1246} 1247 1248static int bme680_runtime_resume(struct device *dev) 1249{ 1250 struct iio_dev *indio_dev = dev_get_drvdata(dev); 1251 struct bme680_data *data = iio_priv(indio_dev); 1252 int ret; 1253 1254 ret = bme680_chip_config(data); 1255 if (ret) 1256 return ret; 1257 1258 return bme680_gas_config(data); 1259} 1260 1261EXPORT_RUNTIME_DEV_PM_OPS(bme680_dev_pm_ops, bme680_runtime_suspend, 1262 bme680_runtime_resume, NULL); 1263 1264MODULE_AUTHOR("Himanshu Jha <himanshujha199640@gmail.com>"); 1265MODULE_DESCRIPTION("Bosch BME680 Driver"); 1266MODULE_LICENSE("GPL v2");
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